More speculatively, and thus less likely, the iPhone 4X might do one or more of the following:

An SD slot for transferring photos and perhaps other data. This is more likely for the next iPad than the next iPhone, but if the iPad gets it, Apple may bring it to the iPhone for consistency. (Apple added SD slots to its last MacBook refresh, so there's evidence that Apple sees value in the technology.) Still, Apple's dislike of cases with lots of openings may lead it to offer a more compact version of its SD-equipped iPad Camera Kit instead.

Enhanced haptic response. That means more tactile feedback from the touchscreen, to allow for richer user experiences and easier access when not looking at the screen.

A MicroUSB port. Apple has agreed to meet new EU regulations that make all mobile phones use the same power connector (MicroUSB), so it may bring that connector to the iPhone 4X. I'm betting, though, that Apple will keep on using its special 30-pin connector and simply provide a MicroUSB adapter for recharging.

What you won't see is a storage expansion bay or slot for apps and device data or a removable battery, despite wish-based rumors in the blogosphere. Both would ruin the simplicity of the iPhone and go against Apple's consistent direction across its mobile and laptop devices.

I suspect the majority of the iPhone 4X's new capabilities will come in iOS and perhaps in application software. For example, we may see more thorough use of voice controls, perhaps an Android-style navigation service, richer photo editing and management tools for the camera-captured images, multiple-user FaceTime sessions, integration of its Voice Memo app into the Notes app, and perhaps some bill-payment options via users' iTunes accounts.

Galen Gruman is an executive editor at InfoWorld focused on mobile and user-facing technologies, an author of more than 40 how-to books, editorial CTO for IDG US Media (InfoWorld's parent company), and an adjunct analyst focused on enterprise mobility at IDC's IT Executive Program.